An organic light-emitting device (also referred to as “organic electroluminescent device” or “organic EL device”) is an electronic device including an anode and a cathode, and an organic compound layer disposed between both the electrodes. A hole and an electron injected from the respective electrodes (the anode and the cathode) recombine in the organic compound layer to produce an exciton, and the organic light-emitting device emits light upon return of the exciton to its ground state. Recent development of the organic light-emitting devices is significant and the developed devices have, for example, the following features. The light-emitting devices can be driven at low voltages, emit light beams having various wavelengths, have high-speed responsiveness, and can be reduced in thickness and weight.
By the way, the creation of a compound suitable as a constituent material for the organic light-emitting device has been vigorously performed heretofore. This is because the creation of a compound having an excellent device lifetime characteristic is important for providing a high-performance organic light-emitting device.
PTL 1 proposes, for example, an iridium complex represented by the following formula as a compound suitable as the constituent material for the organic light-emitting device. In addition, PTL 2 proposes a triphenylene compound as a compound to be incorporated as a host into an emission layer. Further, PTL 3 proposes a hydrocarbon condensed aromatic compound as a phosphorescent red-light-emitting material.
